82 



NORTH AMERICAN FAUNA 68 



Figure 43. — During the grooming period, before hauling out, the sea otter 

 may beat the water to a froth with the front legs, perhaps aerating the fur 

 to some degree. (KWK 55-19-3) 



test was broken completely around the oral orifice before the teeth 

 were employed to remove the broken shell. 



From these observations I have concluded that the sea otter is 

 right-handed. In hundreds of animals observed I have never seen 

 food items brought to the surface under the right forelimb unless 

 the quantity was too great for the left limb to accommodate. 



Handedness in other animals is variable. Warren (1953) dem- 

 onstrated that in the Rhesus monkey the right and left hands are 

 used with about equal frequency. Lane (1946) indicated that birds 

 of prey tend to be left-footed, and parrots (Friedman and Davis, 

 1938) are similar. Pigeons, Fisher (1957) concluded, tended to be 

 right-footed. 



Further study under experimental conditions may reveal if sea 

 otters invariably exhibit right-handedness. 



Tool-using 



The use of a rock or hard-shelled mollusk held on the chest as 

 an "anvil" for breaking the shell of a clam held in the forepaws is 

 discussed under Food and Feeding Behavior. Chest pounding with 

 the forepaws commonly occurs as an apparent expression of frus- 



